trackballInfo method
TrackballInfo?
trackballInfo(
- Offset position,
- int pointIndex
)
override
Implementation
@override
TrackballInfo? trackballInfo(Offset position, int pointIndex) {
final int nearestPointIndex = _findNearestPoint(points, position);
if (nearestPointIndex != -1) {
final Offset preferredPos = points[nearestPointIndex];
if (preferredPos.isNaN) {
return null;
}
final int actualPointIndex = _drawIndexes[nearestPointIndex];
final CartesianChartPoint<D> chartPoint = _chartPoint(actualPointIndex);
return ChartTrackballInfo<T, D>(
position: preferredPos,
point: chartPoint,
series: series,
seriesIndex: series.index,
segmentIndex: currentSegmentIndex,
pointIndex: actualPointIndex,
text: series.trackballText(chartPoint, series.name),
header: series.tooltipHeaderText(chartPoint),
color: fillPaint.color,
);
}
return null;
}